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3 Mar, 2006 "Nightmare"
Posted: Fri Mar 03, 2006 4:25 pm
by David Bryant
Ruud's puzzles have been pretty tough lately, and I haven't been able to employ my favorite technique
for a week or so.
Today's puzzle is different. After completing 18 cells and making a few eliminations with simple coloring,
I found a "5-star constellation" that allowed me to set the value at r6c8. The rest of the puzzle was simple.
I'm just curious if anyone else spotted that pattern. dcb
On a wing ...
Posted: Sat Mar 04, 2006 12:22 am
by keith
David,
I got to this position:
Code: Select all
+-------------------+-------------------+-------------------+
| 2489 2489 48 | 2589 7 6 | 3 1 45 |
| 2689 5 1 | 4 238 2389 | 269 7 69 |
| 3 2469 7 | 259 1 259 | 269 8 45 |
+-------------------+-------------------+-------------------+
| 49 1 34 | 6 23 7 | 5 29 8 |
| 568 368 3568 | 1 9 23 | 4 26 7 |
| 7 69 2 | 58 58 4 | 69 3 1 |
+-------------------+-------------------+-------------------+
| 1 3468 34568 | 3589 458 589 | 7 69 2 |
| 246 7 346 | 239 24 1 | 8 5 69 |
| 258 28 9 | 7 6 258 | 1 4 3 |
+-------------------+-------------------+-------------------+
Then, not in order, two X-wings and three XY-wings will solve the puzzle.
Keith
We're talking about 2 different puzzles ...
Posted: Sat Mar 04, 2006 1:13 am
by David Bryant
Hi, Keith!
You're ahead of me ... I was talking about the "nightmare" for Friday, March 3. You've apparently worked the puzzle for Saturday, March 4, which I haven't even attempted yet!
The puzzle I was talking about looked like this to start.
Code: Select all
.1.....74
.5..8.3..
2....9...
..65.....
74..1..38
.....41..
...2....3
..4.7..8.
63.....9.
Big time zone differences are probably to blame for the miscommunication. I think Ruud is eight hours ahead of MST (mountain
time, where I live) and seven hours ahead of CST (central time in Detroit). He always updates his puzzle pretty promptly at
midnight (for him) -- so if you grab "today's" puzzle after 5:00 pm you'll actually be getting "tomorrow's" puzzle. Ain't globalization grand?
Sorry about the confusion -- thanks for the hint on "tomorrow's" puzzle, though. dcb
Saturday, 4 Mar "Nightmare"
Posted: Sun Mar 05, 2006 12:35 am
by David Bryant
Hi, Keith!
I've finally worked through the "Nightmare" for Saturday, March 4th. I arrived at practically the same position you did, but managed to eliminate three possible occurrences of the digit "6" (at r2c7, r5c2, & r7c2) by simple coloring on "6" before I located the three XY-Wings.
Code: Select all
2489 2489 48 2589 7 6 3 1 45
2689 5 1 4 238 2389 29 7 69
3 2469 7 259 1 259 269 8 45
49 1 34 6 23 7 5 29 8
568 38 3568 1 9 23 4 26 7
7 69 2 58 58 4 69 3 1
1 348 34568 3589 458 589 7 69 2
246 7 346 239 24 1 8 5 69
258 28 9 7 6 258 1 4 3
Now a series of inter-dependent "XY-Wings" solves the puzzle.
1. XY-Wing proceeding from {3, 8} at r5c2 eliminates "2" at r9c6.
2. The "2" in row 8 lies in bottom center 3x3 box; eliminate "2" at r8c1.
3. XY-Wing proceeding from {2, 3} at r4c5 eliminates "4" at r8c3.
4. XY-Wing proceeding from {3, 6} at r8c3 eliminates "4" at r4c1.
And with r4c1 = 9 the rest of the puzzle crumbles like a piece of cheese. dcb
Only Needed an X Wing
Posted: Wed Mar 08, 2006 8:31 pm
by dejsmith
Hi David
After hearing you & Keith rave about this site for awhile, I finally decided to give it a try. The first puzzle I tried took me 2 hours. The next, after more time than that, I needed help from your inputs on this forum. That should give Ruud a nice chuckle. Anyway, this particular one only required an X Wing on 6s in Rows 2&5 for me. I am enjoying this site very much; & I am sure it will get me much better...eventually!!! And, in answer to your original question; No, I did not notice the constellation; but I am not going back to look for it. Ha, ha. Too many other puzzles to work.
Thanks...Dave